Various systems exist currently for implementing reconfigurable antennas. One example is a group of closely spaced patches, where the patches are connected by switches. By opening some switches and closing other switches, the electromagnetic geometry and antenna performance are changed. However, the physical geometry stays the same.
In another example of an existing device, an antenna is connected to a ground and/or a feed through one or more switches. As some switches are opened and other are closed, the electromagnetic properties (e.g., resonant frequency, gain, etc.) of the antenna are changed as well. Once again, the physical geometry stays the same.
A different type of antenna is a telescoping antenna, such as is used with portable radios and televisions. Such antennas are typically monopole antennas constructed of concentric metal tubes that can be pulled out to provide length or retracted to provide compactness. A user can extend the antenna during operation and retract the antenna for storage. Generally, telescoping antennas provide better performance at or near their maximum lengths and often provide adequate performance even when retracted (though the general rule is that the natural resonant frequency will be shifted as the length changes). Currently, however, there is no antenna available that provides acceptable compactness and performance when the antenna is disposed upon a substrate and operates at the same band when compact or expanded.